This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. The goal of this project is to develop more efficacious prophylactic mucosal subunit vaccine candidates that can be used alone or concurrently with the BCG vaccine to develop immunity against tuberculosis (TB). Our studies in mice have identified the alanine proline rich antigen (Apa) of M. tuberculosis as the most promising vaccine candidate for inducing protective immunity against TB. Mice and humans vaccinated with BCG showed higher reactivity to the native (glycosylated) form of Apa of M. tuberculosis than the recombinant (E. coli produced, nonglycosylated) form of Apa. These data suggest that BCG vaccination could be eliciting immunity specific to glycosyl component of Apa protein. We are currently characterizing the immune responses elicited by these two forms of proteins following immunization of mice by intranasal and subcutaneous route. The ability of these two forms of Apa proteins to provide protection will be evaluated by experimentally challenging the vaccinated mice with virulent M. tuberculosis either alone or as part of a multicomponent subunit vaccine along with the other vaccine candidates.